back's
Rear body part's
Back's is the possessive or contracted form of back.
As a possessive, it's uncommon since back rarely takes ownership: the back's support was inadequate.
More often it contracts "back is" or "back has": My back's killing me, She's back's been hurting for weeks.
The contracted forms appear mainly in casual speech.
anatomy
Of the vertebral column
- shoulder'sOf the arm joint
- muscle'sOf a flexor
- body'sOf physical form
- pain'sPossessive of suffering
nerve's · skeleton's · skin's
support
Belonging to a funder
- patron'sOf a supporter
- ally'sBelonging to a friend
- defender'sBelonging to a guardian
- champion'sBelonging to the winner
spine's
Of the vertebral column
- shoulder'sOf the arm joint
- muscle'sOf a flexor
- body'sOf physical form
pain's · nerve's · skeleton's · skin's
tail's
Belonging to rear extension
sponsor's
Belonging to a funder
- patron'sOf a supporter
- ally'sBelonging to a friend
- defender'sBelonging to a guardian
chair's
Belonging to furniture sat upon